Approval of the BMW 801 D at full power. Based on experience to date in its present form, the approval of the BMW 801 D at full power without “Blenden” can be answered for under the following stated conditions:

There is uncertainty as to the best translation of Blenden in an engine context. Presumably it is an orifice, screen or restricted opening/fitting on the BMW 801 D engine.
Another possibility is that Blenden were installed inside the cowling to change the cooling airflow, which might explain the difference between field-modified and new-production aircraft.